However, data from industry analysts IDC suggests there will be 72.1 million wearable tech devices shipped this year; up 173.3% from the 26.4 million in 2014.

Back to the NPD metrics and the AdWeek report suggests that fitness trackers have evolved into a new product category - not one aimed at athletes looking for detailed statistics, but regular folk looking to shift a bit of weight.

"We can expect to see new products emerge that are better focused on the athlete again, driven by the likes of Under Armour," explained Eddie Hold, VP of connected intelligence at the NPD Group.

This argument is supported by IDC's forecasts. "The demand for basic wearables, those that do not run third party apps, has been absolutely astounding," said Jitesh Ubrani, senior research analyst at IDC. "Vendors like Fitbit and Xiaomi have helped propel the market with their sub-$100 bands, and IDC expects this momentum will continue throughout 2015."

Do you own a fitness tracker or smartwatch? Why not talk about it on the brand new Wareable Forum.